CAREER: Nanoscale Order in Metallic Glass Investigated with Electron Imaging and Diffraction

这个职业奖给威斯康星州麦迪逊大学是研究金属玻璃中的纳米级配置使用波动电子显微镜，电子衍射，电子光谱和原子结构建模。 涨落电子显微镜对无序材料中结构顺序的细微变化非常敏感。 由于金属玻璃的不寻常和有用的性能通常归因于某种程度的纳米级原子有序，这些研究可能会提供新的金属玻璃与改进的性能搜索。在最初的实验重点放在高铝含量的玻璃，实验将进行研究，在块体金属玻璃和块体玻璃合金的液态秩序。 该项目的短期目标是了解铝基玻璃结构的各个方面，这些方面控制着失透，以及它们如何随着加工而改变。 长期目标是对金属玻璃中的堆积和局部有序有一个总体的了解，并了解它们的纳米级初级再结晶。 为了让学生掌握在纳米尺度上进行定量测量的工具，将使用电子散射的计算机模拟和电子显微镜数据的数字分析开发定量电子显微镜的新课程。 还将开发一个教学模块，使中学生和教师能够通过研究硬球的堆积来实验性地探索金属晶体和玻璃的原子结构。该项目将支持使用波动电子显微镜（一种先进的电子显微镜技术）进行研究，以测量1纳米长度尺度的金属玻璃结构。 金属玻璃可以非常坚固的重量，或者与通常使用的金属相比，制造出非常好的磁铁。 然而，由于对它们对原子结构的影响的理解不足，定制这些理想性质的尝试受到阻碍。 本项目提出的测量方法将有助于理解材料的结构，从而指导新材料的合成。本项目还将支持开发教育理科研究生和中学生的教育材料。 研究生将教他们先进的电子显微镜技能，他们将需要进入未来的纳米技术劳动力。 中学生的材料将使用简单的硬球包装实验（如玻璃球在罐子里），让学生自己发现指导我们理解金属结构的一般原则。 我们的目标是让学生的感觉做，而不仅仅是学习，科学，从而鼓励他们追求科学事业以后的生活。

This Career award to University of Wisconsin Madison is to study nanoscale configuration in metallic glasses using fluctuation electron microscopy, electron diffraction, electron spectroscopy, and atomistic structural modeling. Fluctuation electron microscopy is uniquely sensitive to subtle changes in structural order in disordered materials. Since unusual and useful properties of metallic glass are often attributed to some level of nanoscale atomic ordering, these studies may provide search for new metallic glasses with improved properties. After initial experimental focus on high Al-content glasses, experiments will be carried out to study order in bulk metallic glasses and the liquid state of bulk-glass alloys. The short-term goal of this project is an understanding of aspects of Al-based glass structure that govern devitrification and how they can be changed with processing. The long-term goal is a general understanding of packing and local order in metallic glasses, and to understand their nanoscale primary recrystallization. With a goal to equip students with the tools to make quantitative measurements at the nanoscale, a new curriculum in quantitative electron microscopy will be developed using computer simulations of electron scattering and digital analysis of electron microscopy data. An instructional module will also be developed to allow middle school students and teachers to experimentally explore the atomic structure of metal crystals and glasses by studying the packing of hard-spheres. This project will supports studies using fluctuation electron microscopy, an advanced electron microscopy technique, to measure the structure of metallic glass at length scales of one nanometer. Metallic glasses can be very strong for their weight, or make exceptionally good magnets compared to the metals normally used. However, attempts to tailor those desirable properties have been hampered by insufficient understanding of their effects on the atomic structure. Proposed measurements in this project will help to understand the structure of materials, and therefore guide the synthesis of new materials.This project will also support development of educational materials for educating science graduate students and middle school students. Graduate students will teach them the advanced electron microscopy skills they will need to enter the nanotechnology workforce of the future. The materials for middle school students will use simple experiments in packing of hard spheres (like marbles in a jar) to let students discover for themselves the general principles that guide our understanding of the structure of metals. The goal is to give the students the feeling of doing, rather than just learning about, science, and thereby encouraging them to pursue careers in science later in life.